Photo Credit: Braden Jarvis

West Kaua’i

Today: Breezy. Mostly sunny with isolated showers. Highs around 87 near the shore to around 76 above 3000 feet. East winds up to 20 mph. Chance of rain 20 percent.

Tonight: Breezy. Partly cloudy with isolated showers. Lows around 72 near the shore to around 62 above 3000 feet. Northeast winds up to 20 mph. Chance of rain 20 percent.

Veterans Day: Mostly sunny with isolated showers. Highs around 86 near the shore to around 75 above 3000 feet. East winds up to 15 mph. Chance of rain 20 percent.

South Kaua’i

Today: Breezy. Mostly sunny with isolated showers. Highs around 86. East winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows around 72. Northeast winds 10 to 20 mph. Chance of rain 50 percent.

Veterans Day: Partly sunny. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 82 to 87. Northeast winds 10 to 20 mph. Chance of rain 70 percent.

Kaua’i Mountains

Today: Breezy. Partly sunny with scattered showers. Highs 75 to 84 in the valleys to around 67 above 4000 feet. East winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 50 percent.

Tonight: Mostly cloudy. Breezy. Numerous showers in the evening, then showers after midnight. Lows 64 to 70 in the valleys to around 60 above 4000 feet. East winds up to 20 mph. Chance of rain 90 percent.

Veterans Day: Mostly cloudy. Breezy. Showers in the morning, then numerous showers in the afternoon. Highs 74 to 82 in the valleys to around 65 above 4000 feet. East winds up to 20 mph. Chance of rain 90 percent.

North Kaua’i

Today: Breezy. Mostly sunny with isolated showers. Highs 78 to 88. East winds up to 20 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then numerous showers after midnight. Lows 65 to 73. Southeast winds up to 15 mph. Chance of rain 70 percent.

Veterans Day: Partly sunny. Numerous showers in the morning, then scattered showers in the afternoon. Highs 76 to 87. East winds up to 15 mph. Chance of rain 70 percent.

East Kaua’i

Today: Mostly sunny. Isolated showers in the morning, then scattered showers in the afternoon. Highs 76 to 87. East winds 10 to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then numerous showers after midnight. Lows 65 to 76. Northeast winds 10 to 15 mph. Chance of rain 70 percent.

Veterans Day: Mostly cloudy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 74 to 85. East winds 10 to 15 mph. Chance of rain 70 percent.

Detailed Forecast

Synopsis

Trade winds will strengthen today as the subtropical ridge north of the state builds back into the region. Trade winds will strengthen significantly next week from Sunday onward, a back door cold front will move into the islands from the north, producing scattered to numerous showers along with blasting trade winds for all islands on Monday and Tuesday. Cooler temperatures are forecast on Tuesday and Wednesday after the front passes. Trade wind speeds will trend lower from Wednesday to Thursday.

Discussion

Satellite imagery this morning shows a low pressure system far northwest of Kauai drifting farther westward away from the state. East of the Big Island a weak easterly wave is observed approaching the Hawaiian Islands and this system will enhance showers along windward and mountain slopes later today over windward Big Island and Maui through Saturday morning near Oahu and Kauai. Passing trade wind showers are forecast through Sunday, favoring windward and mountain areas in the overnight to early morning hours.
Global weather model solutions remain in good agreement with a strong 1040 MB high pressure system moving into the northern Central Pacific basin for the first half of next week. Strong northerly winds on the eastern side of this high center will likely drive colder air and a back door cold front into the islands from the north from Monday night to Tuesday morning. Periods of showers will develop across the state as the frontal cloud band passes through the islands. Much cooler temperatures are forecast, with high temperatures in the high 70's to low 80's are expected after the cold front passes through the island chain from Tuesday to Wednesday.
Very strong trade winds will blow in as the front passes through each island. These strong trade winds will likely reach Wind Advisory thresholds for most areas from Monday to Tuesday. High Wind Warnings are possible over the summit areas of Haleakala on Maui, and the summits of Mauna Kea and Mauna Loa on the Big Island. These blasting trade winds will begin to decrease by Wednesday, and return to more moderate trade wind thresholds by from Thursday onward.

Aviation

Moderate to locally breezy east to southeast winds will shift to the east to northeast by this evening, the result of a weakening trough to the northwest of the islands interacting with a strengthening ridge to the northeast. Ragged clouds and scattered light showers will favor east and southeast facing slopes today and east and northeast facing slopes tonight.
As of 2 am HST, late night satellite imagery revealed a broad area of low-topped cumulus to be about 30 nm northeast of Hilo and moving quickly eastward. Bands of ragged clouds and numerous rain showers should reach the Windward coast of the Big Island by dawn, the east facing slopes and coasts of Maui by mid- morning, and the northeast facing slopes and coasts of the remaining islands this afternoon. Brief MVFR ceilings or visibilities are likely in passing showers, but VFR conditions will nevertheless prevail statewide.
No AIRMETs are currently in effect, but low level turbulence could become a concern this afternoon or evening when wind speeds at summit level are expected to increase.

Marine

A trough of low pressure northwest of the state will shift westward during the next couple days, while a ridge of high pressure builds to the distant north. Fresh to strong east trades will persist through the weekend. The Small Craft Advisory (SCA) in effect for most waters east of Oahu will be limited to waters east of Kaiwi Channel later this morning. The SCA will then be further limited to the typically windy waters around Maui and the Big Island Saturday through Sunday afternoon.
A strong high far to the north of the islands will build southward Sunday night and Monday, strengthening the trades to strong and near Gale levels. The SCA will likely be extended and expand to most if not all waters. Further strengthening of the trades and rising seas is expected following the passage of a strong cold front Monday night into Tuesday, with seas 10 feet or greater and Gale force winds likely across the windier marine zones around Maui and the Big Island Tuesday through Tuesday night and possibly into Wednesday.
A series of small, medium period north and northwest swells will keep some modest surf in place along north and west facing shores through the weekend. The swell will subside Monday, with little to no northwest swell expected Tuesday through late next week.
Surf along east facing shores will remain near seasonal rough and choppy conditions through the weekend. The trades will ramp up quickly over and upstream of the islands giving east shore surf a sizable boost Monday night through next Thursday, potentially to advisory levels. The tradewind swell will also provide some wrap to exposed north facing shores.
Small mainly background south swell energy is expected through middle of next week. A broad gale low, currently just east of New Zealand, is modeled to move east slowly and strengthen a bit more over the next couple of days. This low will generate a small, long period south swell that could arrive locally towards the second half of next week and produce surf near summer average.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 AM HST early this morning for Oahu Windward Waters, Kaiwi Channel.
Small Craft Advisory until 6 AM HST Saturday for Maui County Windward Waters, Big Island Windward Waters.
Small Craft Advisory from 6 AM this morning to 6 AM HST Saturday for Maui County Leeward Waters.
Small Craft Advisory from 6 AM this morning to 6 PM HST Sunday for Maalaea Bay.
Small Craft Advisory until 6 PM HST Sunday for Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

Data Courtesy of NOAA.gov